The Combined Approach When Assessing and Mapping Groundwater Vulnerability to Contamination by ProQuest

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									J. Water Resource and Protection, 2010, 2, 14-28
doi:10.4236/jwarp.2010.21003 Published Online January 2010 (http://www.scirp.org/journal/jwarp)



    The Combined Approach When Assessing and Mapping
        Groundwater Vulnerability to Contamination
                                                           Massimo V. CIVITA
                               Applied Hydrogeology at the Poltecnicodi Torino, Torino, Italy
                                             E-mai: Massimo.civita@polito.it
                     Received October 12, 2009; revised November 11, 2009; accepted December 4, 2009

Abstract

In early 1980’s, the Italian scientific community, together with a number of institutional decision-makers,
realized how urgent it was to protect natural and environmental resources. They agreed that an adequate level
of scientifically organized knowledge allows the accurate planning and development of environment systems
through the management and direction of the effective development process, but without stopping it. Since
the special VAZAR1 project was first set up in 1984, as part of the GNDCI-CNR2 scientific context it has
been the cardinal center point of Research National Program “Aquifer Vulnerability Assessment”. The prob-
lem of groundwater contamination was examined in this program for the very first time in Italy in an organic
and extensive manner as a key for forecasting and prevention purposes. The Italian approaches to assessing
and mapping groundwater vulnerability to contamination are essentially based on two main methodologies: 1)
the GNDCI Basic Method [1,2] a HCS type approach that can be used for any type of Italian hydrogeologic
situation, even where there is a limited number of data. A unified legend and symbols are also defined for
each hydrogeologic level. 2) The SINTACS method [2,3], a PCSM developed for use prevalently in areas
with a good data base coverage. The methodological approaches described in this paper now make up the
Italian standard which has been dealt with in the recent very important Italian Law (152/993) and which are
now ratified in the national guidelines [4] produced by ANPA, the Italian National Agency for Environment
Protection. The methods, besides Italy [5] have been applied in several other Countries [6–10] and others.

Keywords: Groundwater Vulnerability, Contamination, GIS, SINTACS R5, Basic Method

1. Introduction                                                           zone down to the underlying saturated zone of the aqui-
                                                                          fer system;
The intrinsic (i.e. natural) vulnerability of aquifers to                    2) The groundwater (and/or a fluid contaminant) flow
contamination is “the specific susceptibility of aquifer                  dynamics in the saturated zone;
systems, in their various parts and in the various geomet-                   3) The residual concentration of the contaminant as it
ric and hydrodynamic settings, to ingest and diffuse fluid                reaches the saturated zone, compared to the original
and/or hydro-vectored contaminants, the impact of which,                  concentration, which indicates the aquifer attenuation
on the groundwater quality, is a function of space and                    capacity of the contaminant impact.
time” [11]. The intrinsic vulnerability depends on three                     The previously mentioned factors in turn depend on
main factors:                                                             the different possible synergies of several parameters of
   1) The ingestion process and the time of travel of wa-                 a hydrogeologic and anthropic nature, and which are
ter (and/or a fluid contaminant) through an unsaturated                   therefore subject to change in each area.
1
                                                                             The attenuation process that takes place inside an aq-
 The acronym stands for “Vulnerability of Aquifers in High Risk Zones”.
2
  GNDCI-CNR stands for National Group for the Defence against Hy-
                                                                          uifer system (i.e. soil + unsaturated zone + saturated
drogeologic Disasters of the Italian National Council of Research.        zone) as it receives a contaminant (fluid and/or water
3
  Law Decree n. 152, May 11 1999 “Orders on the protection of water       vectored) depends on the properties and primary concen-
against contamination” and acknowledgement of the 91/271/CEE Di-          tration of each contaminant but also on the reactivity of
rective regarding the treatment of urban wastewater and the 91/676/
CEE Directive regarding the protection of water against contamination
                                                                          the system, which can be reduced or, in the long term,
by nitrates from agricultural sources.                                    completely depleted in time. Thus, when a CSC4 impact


Copyright © 2010 SciRes.                                                                                                   JWARP
                                                                M. V. CIVITA                                                         15

persists for a long time or if a contaminant is persistent          several different approaches applied to the same sam-
and mobile, the attenuation capacity of the soil dwindles           ple-area [2], the choice of the method that is most suit-
and vulnerability increases in time. In these cases,                able to build a vulnerability map for a certain area
groundwater protection is only aided by the time of                 should initially depend on a strictly realistic evaluation

								
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